The 3rd Generation Partnership Project (3GPP) has launched, based on existing 2nd generation (2G) mobile telecommunications and 3rd generation (3G) mobile telecommunications networks, an evolved packet system (EPS). An EPS network includes an evolved universal mobile telecommunication system territorial radio access network (E-UTRAN) and an evolved packet core (EPC) network. At an early stage of EPS network construction, an operator has already had a mature circuit switched (CS) network; however, the EPS network processes only a packet switched (PS) service. In view of protection for CS network investment and a policy on EPS network deployment, the operator may use an original CS network device to provide a CS service. To meet this requirement, 3GPP expands a function of a Gs interface between a mobile switching center/visitor location register (MSC/VLR) and a serving GPRS support node (SGSN) that are on the existing 2G or 3G network, and defines an SGs interface between the MSC/VLR and an mobility management entity (MME) on the EPC network. Based on a function of the SGs interface, 3GPP proposes a CS fallback (CSFB) technology and a short message service message over SGs (SMS over SGs) technology. By means of the CSFB technology, a user equipment (UE) covered by an the E-UTRAN falls back to a CS domain on the 2G or 3G network by using the E-UTRAN when a CS voice service needs to be processed, so as to complete processing of the CS voice service. By means of the SMS over SGs technology, the UE residing in the E-UTRAN reuses an existing CS domain device to implement transmission of a short message service message in the CS domain.
To greatly reduce high deployment costs of a radio access network for an operator, 3GPP proposes an idea of network sharing, that is, public land mobile networks (PLMN) of multiple operators or multiple PLMNs of one operator can share a same radio access network to provide a radio communication service. Similarly, for the CSFB technology and the SMS over SGs technology, an operator proposes a requirement for CS domain network sharing, which mainly has the following two scenarios:
Scenario 1: A conventional operator upgrades an existing CS domain network (including a 2G network or a 3G network), to support the CSFB technology and the SMS over SGs technology, that is, the operator can provide, by sharing multiple PLMNs operated by the operator or sharing a PLMN of another operator by signing a roaming agreement, a CS service for a UE residing in an E-UTRAN.
Scenario 2: An operator who provides an emerging pure PS service rents a CS domain network from a conventional operator by signing an agreement, to support the CSFB technology and the SMS over SGs technology.
In the foregoing scenarios of CS domain network sharing, multiple available PLMNs may provide a CS service for a same UE residing in an E-UTRAN. During a combined attach procedure or a combined tracking area update procedure that is initiated by the UE, if multiple available PLMNs provide a CS service for the UE, an MME selects a proper PLMN according to a PLMN, location information of a tracking area in which the UE is currently located, and a CS domain network selection policy of an operator, where the PLMN, the location information, and the CS domain network selection policy are reported by an evolved node B (eNB). A corresponding CS domain location area identity (LAI) is allocated, based on the selected PLMN and the location information of the tracking area in which the UE is located, to the UE, and an associated MSC/VLR is selected based on the LAI. After the combined attach procedure is complete, the UE receives an attach accept message sent by the MME, where the attach accept message carries a tracking area identity list (TAI list), an LAI, and a VLR temporary mobile subscriber identity (TMSI). For the UE, that the LAI and the VLR TMSI is acquired by the UE means CS domain attaching is successful.
After the combined attach procedure is complete, the UE successfully registers with a network of an operator, and the UE needs to display a name of the registered network; or after the combined tracking area update procedure, the UE needs to display a name of a registered network. Currently, displaying of a network name by the UE is mainly based on two policies.
Policy 1: A network side does not perform a configuration, and the UE displays a network name according to a configuration of the UE.
Specifically, the UE displays, according to a PLMN identity (ID) of a currently registered network, a network name corresponding to the PLMN ID.
However, in some scenarios, the UE cannot determine which PLMN ID corresponding to a network name to be display.
Policy 2: A network side delivers a to-be-displayed network name to the UE.
When receiving the network name delivered by the network side, the UE may use the received network name to update a network name configured by the UE, and display the updated network name.
1) An MME informs the UE of the to-be-displayed network name by using an E-UTRAN mobile management information (EMM information) message, and the UE displays the informed network name, where the network name informed by the MME is determined by the MME according to a home PLMN (HPLMN) of the MME.
2) An MSC/VLR delivers a network name of a CS domain network, with which the UE registers, to the MME through an SGs interface. The MME informs the UE of the to-be-displayed network name by using the EMM Information message, and the UE displays the informed network name, where the network name informed by the MME is a network name that is of the HPLMN of the MME and is determined by the MME according to a policy of the MME, or a network name of the CS domain network with which the UE registers by using the MSC/VLR.
However, in the policy in which the network side delivers a network name to the UE for displaying, in some scenarios, the UE cannot determine a to-be-displayed network name, and the MME does not learn which network name is displayed on the UE either.